ISLAMABAD, Pakistan (CNN) -- Pakistani forces early Thursday demolished the front walls of a radical mosque, where battles between security forces and students have raged for two days, intelligence and military sources told CNN.

Radical students sit in a holding area Wednesday after surrendering.

By loudspeaker, the forces warned students inside the Lal Masjid, or Red Mosque, that they had one last chance to surrender before a full attack took place.

More than 1,200 of the students have already surrendered, but hundreds more remain inside.

The attack came hours after the mosque's top cleric was arrested while trying to slip away wearing a traditional woman's burqa.

At least 24 people, including two members of the security forces and one journalist, have been killed in the two days of battles.

Tensions have been simmering between police and students at the mosque, who are blamed for a string of recent kidnappings of civilians, Chinese nationals and Pakistani police. The government has been investigating the activities of the mosque, whose students are demanding sharia, or Islamic law, be instituted in Islamabad.

Brigadier Gen. Tareen of the Pakistan Rangers, head of the military operation at the mosque, said the older students inside were using young boys and girls as human shields.

"We will establish writ of the government at any cost and these people don't have any other choice other than to surrender," he said.

The Pakistan Rangers, a paramilitary group, are conducting the operation with the help of Pakistani police and army. The area around the mosque has been totally sealed, and nobody is allowed to enter or leave.E-mail to a friend